Method of draining and filling multi-pass heat exchanger

Abstract

The invention relates to a heat exchanger assembly with at least one multi-pass heat exchanger, comprising a first distributor (1) with a first connection part (1a) for connecting to a fluid line (9), a second distributor (2) with a second connection part (2a) for connecting to a fluid line (9), and at least one first deflection distributor (4), as well as a plurality of tube lines (5) through which a fluid, in particular water, can flow, wherein the first distributor (1) and the second distributor (2) are arranged at one end (A) of the heat exchanger assembly, the deflection distributor (4) is arranged at the opposite end (B) and the tube lines (5) extend from the one end (A) to the opposite end (B), and wherein the first connection part (1a) is arranged at a lowest point (T) or at least near to the lowest point (T) of the first distributor (1) and the second connection piece (2a) is arranged at a lowest point (T) or at least near to the lowest point (T) of the second distributor (2). In order to allow for the heat exchanger assembly to be quickly filled with the fluid and quickly emptied, a third connection part (3) is arranged on the first distributor (1) and/or on the second distributor (2) at a highest point (H) or at least near to the highest point (H) of the respective distributor (1 or 2), and at least one ventilation opening (10) is provided at a highest point (T) or at least near to the highest point (T) of the deflection distributor (4) for pressure equalisation with the environment.

The invention claimed is: 
     
       1. A method for operating a heat exchanger assembly having at least one heat exchanger comprising:
 a first distributor formed as a tubular manifold and having a first connection piece for connecting to a first fluid line, 
 a second distributor formed as a tubular manifold and having a second connection piece for connecting to a second fluid line, 
 at least one first deflection distributor formed as a tubular manifold and having a vent opening, 
 a plurality of pipelines adapted for a fluid to flow therethrough, the plurality of pipelines is comprising a first group of pipelines serving as supply lines and a second group of pipelines serving as recirculating lines, wherein at least some of the pipelines of the first group of pipelines is connecting the first distributor with the first deflection distributor, 
 wherein the first distributor and the second distributor are arranged at a first end of the heat exchanger assembly and the deflection distributor is arranged at a second end thereof and the pipelines extend in a longitudinal direction of the heat exchanger from the first end to the second end and run at least essentially parallel to one another and are inclined to a horizontal plane with an angle of inclination between 0.5° and 5°, 
 wherein the first connection piece is arranged at a lowest point or at least near the lowest point of the first distributor and the second connection piece is arranged at a lowest point or at least near the lowest point of the second distributor, 
 selecting an operating mode for the heat exchanger assembly depending on ambient parameters, the operating mode being selected from the group consisting of a recooling mode, an emptying mode, a filling mode and a standby mode, wherein when the emptying mode is selected, the fluid flows by gravity out of all of the pipelines into the first distributor and the second distributor and thereafter from the first distributor and the second distributor via the first and the second connection piece into the first fluid line and the second fluid line, and wherein when the filling mode is selected, the fluid flows against gravity out of the first distributor and the second distributor into the pipelines. 
 
     
     
       2. The method of  claim 1 , wherein on the first distributor and/or on the second distributor a third connection piece is arranged at a highest point or at least near the highest point of the respective distributor, and wherein the vent opening is arranged at a highest point or at least near the highest point of the first deflection distributor, further comprising using the vent opening for pressure equalization with the environment. 
     
     
       3. The method of  claim 2 , further comprising introducing the fluid in the recooling mode into the heat exchanger assembly via the first connection piece at the lowest point or at least near the lowest point of the first distributor and discharging the fluid via the third connection piece at the highest point or at least near the highest point of the second distributor. 
     
     
       4. The method of  claim 1 , further comprising operating the heat exchanger assembly in the standby mode after the emptying mode, in which the pipelines are at least substantially empty. 
     
     
       5. The method of  claim 1 , further comprising switching the operating modes of the heat exchanger assembly by actuation of valves of the heat exchanger assembly. 
     
     
       6. The method of  claim 5 , wherein the switching of the operating modes is performed by electrically controlling the valves. 
     
     
       7. A method for operating a heat exchanger assembly having at least one heat exchanger, which comprises a first distributor having a first connection piece for connecting to a first fluid line, a second distributor having a second connection piece for connecting to a second fluid line, at least one first deflection distributor, and a plurality of pipelines adapted for a fluid to flow therethrough, wherein the first distributor and the second distributor are arranged at a first end of the heat exchanger assembly and the deflection distributor is arranged at a second end thereof and the pipelines extend from the first end to the second end, and wherein the first connection piece is arranged at a lowest point or at least near the lowest point of the first distributor and the second connection piece is arranged at a lowest point or at least near the lowest point of the second distributor, the method comprising
 selecting an operating mode selected from the group consisting of a recooling mode, an emptying mode, a filling mode and a standby mode for the heat exchanger assembly depending on ambient parameters selected from the group consisting of outside temperature, wind speed and inlet temperature of the fluid on entering the heat exchanger assembly, 
 detecting one or more of the ambient parameters by sensors and transferring the detected one or more ambient parameters as measured values to a control device, and calculating in the control device an outlet temperature of the fluid as it exits the heat exchanger assembly based on the detected measured values. 
 
     
     
       8. The method of  claim 7 , further comprising operating, by the control device, the heat exchanger assembly in the recooling mode as long as the calculated outlet temperature is greater than or equal to a predetermined limit value and switching the heat exchanger assembly to the emptying mode when the calculated outlet temperature is below the limit value. 
     
     
       9. The method of  claim 7 , further comprising switching, by the control device, the heat exchanger assembly from the standby mode to filling mode as soon as the calculated outlet temperature is greater than or equal to a predetermined limit value. 
     
     
       10. The method of  claim 7 , wherein the predetermined limit value is greater than 0° C. 
     
     
       11. The method of  claim 7 , wherein the predefined limit value is determined as a function of the thermal capacity of the heat exchanger assembly. 
     
     
       12. The method of  claim 7 , wherein the heat exchanger assembly comprises a plurality of heat exchangers which are each controlled by the control device and adapted for independent operation, further comprising controlling, by the control device, one or more of the plurality of heat exchangers to operate in the recooling mode as a function of the detected ambient parameters and/or the detected inlet temperature of the fluid. 
     
     
       13. The method of  claim 12 , wherein the fluid volume conducted through the heat exchanger assembly per unit of time remains the same regardless of the number of heat exchangers operated in the recooling mode.